1. Field of the Invention
The present invention relates to a head-mounted picture display device having optical systems for projecting pictures formed on picture display members so as to be visualized by the observer.
2. Description of the Related Art
In recent years, various head-mounted picture display devices including a so-called head-mounted display (hereinafter an HMD) have been proposed as compact display devices used to display and enjoy pictures or play various kinds of games. The head-mounted picture display device has been put to practical use for such purposes.
For example, an eyeglasses-like picture display device has been disclosed in Japanese Unexamined Patent Publication No. 5-264946. Herein, the face 51 of a main unit 50 thereof is, as shown in the perspective view of FIG. 7, formed with a convex translucent member. The top 52, bottom 54, and back 53 of the main unit 50 are formed with opaque plane members. The main unit is formed as a whole with a hollow housing that is part of a hollow cylinder. A pair of eyepiece windows 53a is formed in the back 53 of the main unit 50 at positions at which they will be placed to oppose the observer""s left and right eyes during use. Moreover, a nose rest portion 54a shaped like an inverted letter V is formed in the center of the bottom 54. Furthermore, left and right supporting frames 55 capable of being mounted on the observer""s head are attached to the main unit 50.
However, in the eyeglasses-like picture display device disclosed in the Japanese Unexamined Patent Publication No. 5-264946, when the main unit 50 is mounted on the head, a pair of bows must be hung on the left and right ears. Since the main unit 50 is shaped like part of a cylinder, it is heavy and bulky as a whole. Moreover, since a translucent member and opaque members are united with one another, workability is poor in terms of maintenance of optical parts and other units incorporated in the main unit. Consequently, the handling efficiency of the device is very poor.
The present invention attempts to resolve the foregoing drawbacks. An object of the present invention is to provide a user-friendly head-mounted picture display device having a lightweight main unit and capable of withstanding long-term use.
A head-mounted picture display device in accordance with the present invention comprises predetermined picture display members, optical systems, and a housing body. The optical systems project pictures formed on the picture display members to be viewed by the observer. The housing body accommodates the picture display members and optical systems and retains them at viewable positions at which they lie closely to or in contact with the observer""s head. The housing body has a pair of window frames located at positions at which when the observer assumes a predetermined viewing posture, the window frames are opposed to the observer""s eyes. A back cover member holds transparent window members in the window frames. A front cover member is fixed unitedly to the back cover member. Vertical cross-sections thereof passing substantially through the centers of the pair of window frames are each shaped to have an apex or convex part projecting in a direction opposite to the window frames. Moreover, the vertical cross-sections each have two surfaces which extend along lines inclined upward and downward from near the apex or convex part towards each window frame.
According to the present invention, the head-mounted picture display device comprising the foregoing members can provide a lightweight main unit, can withstand long-term use, and is user-friendly.
Other features and advantages of the present invention will be fully apparent from the description below.